UFC president Dana White has warned that Michael Bisping's rumoured upcoming bout against Vitor Belfort "is not a done deal".

White made the announcement on Tuesday, after speculation that middleweight Bisping was set to face the former light-heavyweight champion as the main event of a January card in Brazil.

But White has now cast doubt on the match-up - after asserting that a deal that would see Belfort, who fought for the middleweight title at the start of 2011, face the Englishman has not yet been sealed.

Belfort also denied any knowledge of an impending announcement over the weekend, saying: "I don't have anything confirmed about fighting Bisping. It's all rumours. When I know about it will let you guys know."